Art and science meet in my adventures in sketching astronomical objects. Here I detail my travels across Australia with my telescopes, and from home, the people I meet and the technical challenges I encounter. From our closest neighbour, the Moon, to the furthest galaxies. From the seemingly trivial to the mind bending complex. All is fair game for my sketch pad. And continuing the tradition of The Mellish Technique.

Moon

Thursday, 4 December 2014

You will find this page listed in the left hand column too in the 'pages' heading.

Here I will post pictures of my telescopes, modifications I make to them, and sources of inspiration from other telescope makers that are wonderful ideas.My first posting their is up, and answers a focusing problem when your instrument's focusing knob is small in diameter. Please have a look and enjoy.Alex.

Poor weather and work continue to conspire against me to have time with a telescope and pencil & paper.This week I've posted my sketch of the chance find of not one but two Lunar X's, one an imposter that I found first, and then the better known Real McCoy from out of an artistic flourish.You will find a more in-depth account of the sketch in the Gallery of astronomy art pieces.

Tuesday, 25 November 2014

Small rich field telescopes can be too easily overlooked for larger apertures. The problem with this is the larger picture of the way individual objects relate to their immediate neighbours can be lost.This sketch was done back in April during the Ice In Space Astro Camp. It is one of my all time favourite areas of the sky, and it requires the right instrument to take in the enormous area of sky.A more extensive write up of this piece can be found in the blog page Gallery of astronomy art pieces.

Wednesday, 15 October 2014

This sketch is the third time I’ve visited the magnificent
trio of craters Ptolemaeus, Alphonsus & Arzachel. Each and every time this trio has given
incredible new details & stories.

Much of the Moon’s details are readily visible – they just
requires patience to identify. Other
details are fine & require not just patience, but a co-incidence with good
stable atmospheric conditions.

The exercise in producing this piece revealed more about the
forces that formed the lunar surface.
Many of these forces spell cataclysmic results if they are visited on
Earth now. Others are currently in play
on Earth today, though extinguished on the Moon long, long ago. My last examination of this trio show me how
the appearance of craters can show the age of their features, thereby giving a
time-line to their relative age/history.

Brief history in the rocks – The more a crater is lava
filled/flooded, the older it is as the impact occurred when the Moon was hotter
and its crust was thinner, so lava flowed readily to fill the resulting
hole. As the Moon cooled, and the
crusted thickened, the lava flowed less readily, so these craters show less
filling/flooding, with their central peaks still visible. The latest age of the of the Moon sees
craters with no lava flooding as the crust is too thick to allow lava to flow
to the surface. Today, the Moon is a
nearly totally cold rock, so every impact is a ‘simple’ impact – very recent research by Japanese scientists
has revealed the very core of the Moon still maintains a small amount of
residual heat.

Now, the really exciting part of this ancient lava activity
is that these partially filled craters hold a bucket load of other details such
as extinct volcanos, pyroclastic deposits (ash and dust fallout deposits),
rilles that are river beds of lava flows, and other rilles that are extensive
fracture lines produced by the massive subterranean magma pressure pushing up from
below the solidified flooded crater floor, causing the solid lava floor to dome
and fracture. This is a common characteristic
of these middle age craters. Older
craters like Ptolemaeus, rarely show this type of rille system.

This trio of craters show all these classic
characteristics: Ptolemaeus is a very
ancient crater where the entire crater is flooded, with only a shallow rim
remaining.

Alphonsus is younger than
Ptolemaeus. It’s floor is considerably
flooded with just a small amount to the central peak visible. As volcanic activity was still a common
occurrence, Alphonsus has several volcanic peaks and pyroclastic deposits. Its floor was also subjected to the
subterranean magma pressures that have
created a series of rilles in its floor.

Arzachel is the youngest of the trio.
It is still a very old impact crater as its floor is flooded, but by the
least amount of the three. Volcanism was
already not as active on the lunar surface so there are not volcanos in
it. However, subterranean magma pressure
was still very much in play and these significant forces, and having no place to go
such as volcanic vents, pushed very hard on the partially flooded floor and
fractured it too.

There is another set of crater features that are really
special as they do not occur too often on the Moon. ‘Catena’ is the Latin name for chain, and on
the Moon these refers to a string or chain of craters. These chains are formed by an asteroid or
comet that has been smashed and its component fragments orbit the sun in a line
following each other. When they
encounter the Moon, their impact is seen as a dotted line. On either side of Ptolemaeus there are two
such catena. One on the left of the Ptolemaeus
is Catena Davy, named after the crater Davy.
It is a challenging thin string of beads going east to west. This chain can be a tease to find as the
constituent craters are small, going from 1km to 3km. The second set of catena is on the right side
of Ptolemaeus, though I cannot find this catena’s name in the atlas’s at my
disposal.

The area surrounding this trio also has several fault lines
and rifts that are not expressly named. Two
of these sets of fault lines also straddle the left and right sides of
Ptolemaeus, running parallel down to the north west. Curious that these should not be named as
they are quite striking and bold features.

This visit to this prominent trio was one of my most
exciting pieces to produce. So much more
detail was found this time than the previous two. It is also the most expansive of the three
sketches. And a wonderful time was had.

Wednesday, 1 October 2014

This piece so far has been the most challenging for me. The level of complexity is just an extraordinary thing. From bright nebulosity, through to angle's-breath faint. Intense bright clusters, through to vast space between stars. This piece I ended up working on over two nights as it required me to develop new techniques to depict certain details.

The Tarantula is so named for its somewhat arachnid appearance. Tendrils of nebulosity, fashioned from the extraordinary push and pull of stellar radiation and strong gravitation influences, give this nebula its spridery appearance. It sits on the edge of the Large Magellanic Cloud closest to the Milky Way galaxy. The gravitational tidal pull between the Milky Way and that of the Large Magellanic Cloud (LMC), has acted to create a massive compression front at this point of the LMC. The compression front has triggered an enormous amount of stellar formation activity. Such stellar formation activity is also witnessed in other galaxies that have also experience massive gravitational tidal influence by the interaction with another galaxy.

What cannot be forgotten is the clusters of super massive stars that powers' the glowing mass of gas and dust. These same stars were born from this gas and dust. The radiation that they blow of creates new compression fronts within the gas cloud. These compression fronts within the gas cloud creates concentrations of this gas and dust. This increase in the mass density results in a localized increase in gravity. Over the course of millions of years, this ever so slight localized gravitational pull attracts more material onto itself, and this slowly builds and builds until a star is born out of this dust and gas. Many of the super massive stars that are inside these huge clusters are burning their hydrogen fuel at such a staggering rate that their life span is short - tens of millions of years as opposed to several billion for our Sun. Finally, when their hydrogen fuel is exhausted, they undergo a cataclysmic explosion, spewing themselves back into the space that they were formed from, and from their ashes new stars will be born.

From a dark site, the Tarantula is also a naked eye object, seen as a large dot off one of the general bar-like appearance ends of the LMC. And it is a massive structure. The LMC is some 160,000 light years away from us, and the Tarantula is still visible as a unique solitary item in the sky. It is some 100 times larger than the Great Orion Nebula. Were the Tarantula at the same distance to us as the Great Orion Nebula, its brilliance would be enough to cast shadows on Earth.

This nebula has presented a great creative challenge for me. I spent two and a half hours on it the first night. The details within the tendrils confounded my capabilities to depict accurately that night. I ended up exhausted and frustrated. The following day I experimented with techniques to achieve the effects I was after. Last Saturday night I paid another visit to the Tarantula, armed with the new techniques. This time around, not only was I less daunted, but it afforded me greater freedom to more critically examine the fainter details. I was surprised at how much more detail I was able to detect now not being so concerned with details I was struggling to depict in a satisfactory manner.

All up I spent close to 5 hours at the eyepiece with this piece. The Tarantula has proven to be a fantastic challenge, and a wonderful inspiration. Again, it is through the time taken in developing a sketch that the full splendor that the Tarantula was revealed.

Thursday, 25 September 2014

This last Saturday ended up being a non-event sadly. When we arrived we were greeted with a
magnificent clear sky. Some 13 people
turned up to the Airfield in hope of some photons. Then, no sooner had we set up out telescopes
the wind changed to come from the east, and with that the clouds rolled in… so
very disappointing. We are hoping for
better skies this coming Saturday.

I did manage a mid-week sojourn to the Airfield, seeing that
the forecast was favourable. The current
forecast for the coming Saturday wasn’t too promising at the time, so I took
the chance in case the worst came about (the forecast now is much more
promising though!).

A recent supernova in the galaxy NGC 1566 made me curious
about it and Seyfert type galaxies. I
ended up getting one of the most spectacular surprises I’ve encountered for
some time! It also brought to mind
something I had read about exit pupil when observing galaxies.

What a magnificent, beautiful galaxy NGC 1566 is! Low magnification does not do justice to
it. It really requires some grunt to see
the wealth of details it contains.
Seeing this night was very stable, so I was able to take things to 200X
in my 17.5” Karee dob. Low magnification
showed nothing more than a small bright oval.
Increasing the magnification and a gorgeous pair of arms became starkly
evident. A bright stellar like core too. The increased contrast offered by the
increase magnification also showed a
gossamer faint extension beyond that of the arms only visible with averted
vision.

The ultimate treasure 1566 held was still to be
surrendered. Carefully studying the arm
structure for while sketching, I noticed that one of the arms has a ‘string of
pearls’ along its leading edge of strong star forming regions. The other arm has similar regions, but not as
many nor as bright. This string of star
formation regions was most unexpected, and absolutely exquisite to view.

In so far as the supernova is concerned, while it was still
visible, it was not bright enough for me to distinguish it from the bright core
and a bright foreground star that it sat between. The separation between the core and this foreground
star was just too tight.

If you have the opportunity to view this little galaxy,
please do. While small, it is bright and
takes high magnification very well to reveal a large amount of detail. If it were not for that this galaxy sits in the same constellation as the Large Magellanic Cloud it would most likely be much more well known.

Wednesday, 17 September 2014

Hello folks,With the September new Moon sitting mid-week, we have the chance of getting two good dark sky weekends this month, one either side of the new Moon.It's been an abysmal year this one so far for using Katoomba Airfield. We have not had one single new Moon weekend fall in our favour! Dreadful weather has befallen each and every new Moon weekend for us this year. There are some regular visitors to the Airfield who have not had their scopes out for over a year with work also conspiring against them. Very sad state of affairs this one.This weekend is looking very promising though. I'm hoping it will be a very productive one for me too.If ever you do come down to Sydney, see if you can manage to pair it up with a new Moon weekend. This makes for the best opportunity to get out under a southern dark sky. Maybe even look into meeting up with us fellows who make the trek to Katoomba Airfield once a month or so. It would be great to meet you.The Airfield its 1000m above sea level, making it one of the highest observation points within 2 hours of Sydney's centre. This helps so much in toning down the light dome coming from Sydney as the majority of it sits in a natural basin below the Blue Mountains. When conditions have been at their best, I've managed to see the Pinwheel galaxy, M33, as a naked eye object.I'll be taking along a 12" Marana dob and a 17.5" Karee dob, both from Gondwana Telescopes. I'm happy for people to come and use both these fine instruments. Lots of photon collecting power between these two scopes :) Fingers crossed for a good couple of dark sky weekends.The picture below is from one of our summer nights a couple of years ago.

Tuesday, 9 September 2014

One part of my intention to start this blog is to also make it a place where I can also put up works that I completed prior to starting the blog, and a place to showcase newer pieces as they fall into the blog's archive.So here is theGallery of Astronomy Art.

You can also access the Gallery from the link in the left hand margin.Tonight I'm adding my sketch of M16, the Eagle NebulaThis was my first ever view of the dark pillars that form this famous avian celestial apparition. It was a fortunate viewing too as only a short time after I completed the sketch conditions deteriorated and the dark pillars were no longer visible in my 17.5" scope.Even to see this Eagle is not an easy task. Averted vision is a must, and patience. Yet the reward is fabulous as it is possible to make out a brighter leading edge on one side of the pillars, making for a fantastic 3D effect.Object: M16, the Eagle NebulaTelescope: 17.5" Karee push-pull dobsonianGear: 16mm Konig, 125X, OIII filterDate: 2nd July, 2011Location: Ilford, AustraliaMedia: Soft pastel, charcoal and white ink on A4 size black paper

Tuesday, 2 September 2014

Local weather has been abysmal over the last three
weeks. Rain and heavy overcast
conditions killing off any chance of scope time. This last Sunday saw a break in this weather
pattern, and I had an opportunity to visit the Moon again.

First inspection of the Moon threw up a wonderful trio
combination of craters formed by Theophilus, Cyrillus & Catharina (south is
to the top of the work). The image they
presented close to the terminator was most striking. Little did I know of what lay ahead of me. What I thought would be an ‘easy’ cruise was
to turn into a marathon effort at the eyepiece.

These three large craters are very busy places. They are riddled with younger imapacts,
criss-crossed with rilles, damaged and worn with age. The actual amount of detail only slowly became
apparent as the sketch developed and the observation time increased.

All three craters are very ancient. All three have flooded floors, with Catharina’s
(the oldest) central peak completely
covered over, Cyrillus’ central peak just managing to poke through, and Theophilus’
being the least flooded. The ghostly image
of the ray system radiating out from Theophilus is still visible across the
plains of Mare Nectaris, and Sinus Asperitatus to the north. These plains are heavily pock-marked with
thousands of small craters

The longer the sketch when on, the more detail I saw, and
the longer the process went on. What I
had anticipated as a two hour sketch went on for more than three hours. The level of detail is astounding, and
beautiful. While I was cramping up, and
my seat becoming less comfortable, I just could not stop nor reduce the amount
of detail I was putting down.

Then, a little surprise popped up. I spotted a curious looking little ‘crater’
just off the northern rim of Catharina.
The trailing shadow of the rim of this little crater looked way too long
for it to be a normal crater. The length
of the shadow implied a much taller rim wall.
It just could not be a crater.
The only thing it could be was a volcano. I always examine my Moon atlas’s after
completing a piece to check names and features.
Principle of the atlas’s I use is “Virtual Moon Atlas” (VMA). VMA confirmed my suspicion of the unusual nature
of this ‘crater’ as being a volcano!
Woo-hoo! ‘Catharina 2’ is its
official designation. Catharina 1 is to
the south east of Catharina, but it is not as prominent as ‘2’, and in the
sketch is lost in the noise of the surrounding small craters.

Another surprise presented itself along the terminator, with
the lesser known brother to ‘The Straight Wall’ escarpment made its presence
known with the brilliantly illuminated eastern facing wall of Rupes Altai. Unlike The Straight Wall, Rupes Altai is
serpentine in nature. Rupes Altai is
close to 500km long, nearly five times longer than its straight brother, and
has an average height three times taller too.

This piece was an exquisite exercise for me. The amount of detail revealed to me was
fabulous. Detail that is just not
visible without extensive observation time spent on the area. I ended up being dashed on the rocky shore line
of Mare Nectaris, beaten up due to my complacency. And now all the happier for it.

I really hope you enjoy this piece as much as I’ve enjoyed
producing it!

Wednesday, 13 August 2014

This is the third sketch completed over three consecutive
nights. And as often happens, the best
was saved for last.

In November last year I did a sketch of Rimae Hippalus. This area shows a series of what looks like
co-centric riles. When I did some
research on this area after this Rimae Hippalus area, I came so see that there
is a ‘mirror image’ set of riles to the north-west of Rimae Hippalus, Rimae
Mersenius. All of this happens along the
shores of Mare Humorum.

As it turns out, this is no coincidence. Both sets of riles are all related. They are the resulting massive fracture lines
that were formed when an enormous rock slammed into the Moon that formed Mare
Humorum. Both these rile systems are the
fracture lines formed when the thin crust was smashed, much like the fracturing
that forms when a stone or bullet slams into reinforced glass. The terrible destructive force of that
collision not only resulted in the crater being flooded by lava, but much of
the resulting riles were also partially flooded.

Mare Humorum also has other treasures within its lava
fields. A pyroclastic deposit sits on
the southern edge. These areas are
ancient remains of volcanic activity on the Moon! And just west of this long extinct volcano is
another volcanic anomaly, a dome. Domes
are volcanos that force their way to the surface, but not quite rupturing
through. Instead there is a ‘dome’
formed as the pressure from underneath pushed up causing a blister-like effect. While doing this sketch, I noticed an odd
‘mountian’ close to the south western shore, very much out of place as it is
well inside the lava fields. It turns
out that this ‘mountain’ is one such dome!

This entire area makes for magnificent examination. This particular night turned out to have
sensational seeing conditions. This
allowed me so reach the best resolution I’ve been able to achieve for over a
year, with details as small as 2km in diameter.

However, the sensation that is this area is not limited to
the history of rile system. The crater
Gassendi contains an astonishing series of riles within its floor. The floor of Gassendi is a partially flooded
one as the central peak of the crater is still visible. But the resulting lava field is criss-crossed
with a maze of riles. Their curious
structure could well be the result of collapsed lava tunnels. However I am not convinced as yet that this
is the case as these riles are over 3km wide.

Whatever the origin of this valley system, it makes for a
very pretty filigree pattern inside Gassendi.

Object: Mare Humorum
& crater Gassendi.

Telescope: C8, 8” SCT

Gear: 8mm Celestron
Ultima LX, 250X

Date: 7th
August, 2014

Location: Sydney,
Australia

Media: Soft pastel,
charcoal & white ink on A4 size black paper.

Below is the sketch of Rimae Hippalus, done in November last year, which is off the south-east edge of Mare Humorum, showing the rile system that reciprocates those pictured above. You will see the crater Hippalus in both sketches that gives the reference point between both pieces.

Tuesday, 12 August 2014

This night, while conditions didn’t allow for too high
magnification, one striking feature demanded attention. Very little of it was in illumination, but
what was sunlit, made for a gorgeous subject.

Gassendi is a large crater on the northern shore of Mare
Humorum. Being dawn, its eastern face is brilliantly
lit. The crater floor is still in shadow
and inky black. Then, appearing as
fragments of a shattered Moon, the highest peaks of its western rim and its
central peak reaching out from the depths with fingertips to touch the first
rays of the sun.

It was a challenge to depict the strong shadows. And over the course of the two hours at the
eyepiece, it was wonderful to witness the shadows and highlights change as the
sun rose higher and higher. For all the
challenges, there is always something beautiful to behold.

Monday, 11 August 2014

We had a great spell of clear nights last week that allowed
me to do three sketches of the Moon over three consecutive nights. The first was a revisit of Copernicus that I
had sketched the month before but on a more advanced phase.

On this particular night, the phase was two days after
Copernicus’ appearance on the terminator.
This made for a shallower angle of incidence of sunlight so many more of
the smaller secondary craters to be visible.
Conditions on the night were not brilliant, and magnification at 250X still
saw a lot of atmospheric thermal current distortion to the image, limiting how
small the details I could see. With a
bit of perservierence a lot of these secondary craters could be made out. You will find information on the formation of
these ‘secondary impacts’ in my earlier write up on Copernicus below.

Being sooner after sunrise over Copernicus, the shadow
structure made for a more dramatic lunarscape.
Longer shadows, greater contrast, and a visual feast. The surrounding craters that accompany Copernicus
also adding to the drama with there illumination.

Friday, 8 August 2014

M22 is a true jewel of the night sky. This giant globular cluster from a dark site can be a naked eye object as well. It
is large enough for even smaller telescopes to resolve its multitude of
component stars, to reveal its large and intense core.

M22 is beautiful in my 17.5” scope. It is very different from Omega Centauri and
47Tuc – could even describe it as the ‘runt’ of the giant globulars as its core
is not as busy as its bigger brothers.
But the component stars of its core are absolutely brilliant, arranged
in so many signature patterns. It is
slowly turning into a favourite of mine with its understated brilliance, loud
without being overbearing presence, and sitting on a magnificent carpet of the
Milky Way glow.

I won’t say much here.
I’ll let M22 do its own quite whispering of its magnificence. Yeah, I think one firm fav of mine now…

Saturday, 2 August 2014

This was the first sketch I completed at Astrofest. I've been wanting to sketch this beautiful
dark nebula ever since I first laid eye on it some three years ago. This dark nebula, B86, goes by the popular
name of "The Ink Spot". It sits
smack bang in the centre of the densest star cloud in the whole sky, the Cloud
of Sagittarius. And what sets it off
even more is B86 has a gorgeous bright open cluster right next to it, NGC
6570. Both objects are more-or-less the
same size as each other, even though both are not very large themselves. But it is the juxtaposition of these two very
different objects against the blaze of the Milky Way that makes this pair a
spectacular pairing.

Dark nebulae are clouds of dust and gas that are drifting
through the Milky Way galaxy. Many of
these conglomerations of dust and gas do end up being formed into stars and
planets, but most just end up forming the fabric of the galaxy. In fact, the stars that we see actually only
form a small percentage of the actual mass of galaxies. By far the greatest amount of a galaxy's mass
comes from this very dust and gas. The
Ink Spot is a small patch of cloud. It
is a very opaque nebula too. Dark
nebulae are categorised according to their opacity, or how dark they are. The scale of opacity goes from 1 (very
tenuous) through to 6 (very opaque).
While the opacity of The Ink Spot may be a 5, it is because that it sits
in the Cloud of Sagittarius that makes is a striking object.

The little open cluster NGC 6520 really works very well in
setting off B86. Open clusters are
groupings of stars that are all related to each other having been formed out of
the same parent cloud of gas and dust.
Evidence for this is seen in the spectra of the stars displaying the
same chemical make up. The brothers and
sisters of our own Sun have been identified this way, with the same chemical
signature as our Sun having been identified in several close by stars even
though the Sun's 'siblings' have long drifted off away from each other. Open clusters are loose groupings too, so
even though they formed from the same source, their gravitational connection to
each other is not strong enough to keep the group together for too long.

For me, this tiny patch of sky is one of my most favourite. Tiny and oh so precious. Brilliant, dark, stark, ghostly. All in one. Gorgeous.

Thursday, 31 July 2014

Hi all,The trip up to this year's Queensland Astrofest was a marvelous one! I drove up with a mate to share the driving. We made the trip over two days, and saw some amazing country along the way. We took three of my telescopes with us, two 12" dobs (both Marana instruments from Gondwana Telescopes) and the 17.5" (a Karee model also from Gondwana Telescopes) - all packed into the one car along with all our camping gear. That is something you just don't see, but you will in the pictures below :)

I did a presentation of Gondwana Telescopes and held two workshops. The sketching workshop proved so unique and special that I was asked to do another one. Along with my sketching portfolio, a lot of interest in astronomical sketching was created, and this encouraged me immensely.Astrofest is organised between 6 different Queensland astronomy clubs and goes for longer than a week, spanning across two weekends. The entire event for me was a pleasure to experience, getting to meet an extraordinary lot of people all passionate about astronomy and life. If you haven't been to an Astrofest event, I certainly can wholeheartedly recommend you do so.

The grounds on which Astrofest is held also houses its own observatory which contains a beautiful 9.25" Celestron SCT. Accommodation was a choice between camping and bunk houses, and lunch and dinner were available, along with unlimited amounts of tea and coffee to get one through the cold nights. Astrofest is also geared towards families with many people taking the chance to make astronomy a whole family experience.I ended up completing three sketches, two of which were of targets that I've long been wanting to sketch for a long time. The first two nights we were up there through up brilliantly clear skies. Fog rolled in around 2am, but that was fine by me as I had had enough by then anyway.

Sunday, 20 July 2014

With the 45th anniversary of the Apollo 11
landing coming up, I thought I’d post my sketch of the landing site area for some revision of my original thoughts on some formations.

I used to think that these fissures formed as a result of
shrinkage. This was as a result of my
confusing the tiny appearance of these riles through the eyepiece to cooling
shrinkage. But these riles can be over
10km wide, and lava does not shrink this much!
I’m now thinking that these fractures formed when the Moon’s crust was
very thin and experienced a massive impact.
The thin crust then would fracture, and in some instances, like the
impact site itself, fill with lava, like Rile Hypatia. Another recent sketch of mine shows a series
of co-centric fractures – these are more likely also to be the crazing pattern
due to a big impact, not shrinkage.
Examination of the area round Rimae Hippalus makes the likely impact
that formed these fractures as being the one that formed the flooded area of
Mare Humorum. Looks like I’ve changed my
thinking on how these riles form!

One part of science is to be flexible in accepting new ideas when older ones have been disproved or shown to be mistaken. Likewise, old ideas also need to be challenged to double check their voracity. Here is one case where my original think was incorrect, and I've come to a new conclusion following new evidence and correction of original observations.

Wednesday, 9 July 2014

I'll be heading north of the border for three nights under Queensland skies. Will be my longest stay in Queensland and I'm really looking forward to it.I'll be presenting two workshops on the afternoon of Friday 25. One on Observing Tips and the second on astronomical sketching. In the Observing Tips I'll be covering items starting from the anatomy of the human eye and how to make the most of it, telescope types and focal ratio and its significance to observing, eyepieces and their influence, matching telescope design to eyepiece design, filters and how to make the most of them, and practical telescope observing tips.In the sketching workshop I'll be doing practical demonstrations on using the Mellish Technique, covering globular clusters, galaxies and nebulae. I'll be showing how to exploit layering to achieve distinct effects and to develop form and volume. I'll also do a demonstration on how I use the same media I use for the Mellish Technique to produce my Lunar sketches, and how quick and forgiving these materials are.I'll then switch hats on the Saturday to give a presentation for Gondwana Telescopes, demonstrating how these compact and robust instruments assemble into fine, balanced and practical instruments. I hand craft these instruments individually to each primary mirror. I am very proud of these instruments, as much as my sketches.If you are heading to Astrofest this July, I look forward to getting to meet you there.Alex.

Tuesday, 8 July 2014

A second sketch in less than a week! An absolute flood compared to the previous 12
months!

I have sketched the crater Copernicus on other
occasions. I enjoy sketching this
magnificent ray crater as it has so much to offer no matter the phase of the
Moon. Since my last Copernican sketch,
I’ve come to find out more about this 95km diameter hole on the Moon.

The area around the crater Copernicus is fascinating, with so
much lunar history on display – from amongst the oldest to the newest lunar formations. From ‘ghost craters’ nearly totally lost in
lava flows from long ago, to relatively recent, terrifying massive impacts
whose devastating power is very much still visible.

Copernicus sits isolated surrounded by Seas and an
Ocean. These large areas of lava flows occurred
a very long time ago. The ghost crater
is Stadius is nearly as large as Copernicus.
But all we see today is barely the barely visible rim of its crater, the
result of an ancient impact with a very hot Moon that readily flooded the impact
hole with lava.

A newer impact is the crater Erastothenes. In structure it closely resembles Coperniucs
with clear features of large impacts such as central peaks, terraced internal
and external walls (the result of landslides of the steep walls). But it is an older impact than Copernicus
because the rays of ejecta material have been covered over by those of
Copernicus.

The rock that created Copernicus was a massive one. The impact through up an enormous amount
much material. Much was vaporized and pulverzied
that blew way out from the impact zone, being deposited as the rays that we see
today. There are even ‘shadow zones’. These formed when the cloud of polverised
rock raced over a mountain range and
eddie currents were created depositing material behind the ledge.

Another great feature of Copernicus is another set of
ejecta. Rock was not only pulverised but
also ejected out from the impact as huge bolders. These rocks inturn created their own set of craterlets. These craterlets surround Copernicus, even
forming strings of impacts. But these
are not considered Chain Craters as they are the result of secondary impacts
from a larger impact. Chain Craters are
a string of primary impacts. In the
sketch you will see one of the more prominent strings of secondary impacts. These secondary impacts are not trivial ones
either. Some of these craterlets are
over 5km in diameter which would have taken a substantially big rock to have
been thrown out to make such a large crater.
Conditions on the night were not perfect. If conditions were better a whole lot more of
these secondary impacts would have been visible.

This night I also took a photo of myself at the eyepiece
with all the gear I use while sketching.
The white box is a polystyrene box I use as a dew hutch to protect my
materials from dew during the evening. I
also made a video of the sketch. I’ll be
looking at making a time lapse video of this as a 3hour video of the sketch is
not gripping viewing…

Friday, 4 July 2014

Last night I had a chance to sketch a part of the Moon I’ve
been wanting to for a very long time – the landing site area of Apollo 11. While the site itself is invisible to us here
on Earth, there are three craters close to the site that are significant to the
site. These three craters are the ones named
after the three Apollo 11 astronauts, Armstrong, Aldrin and Collins.

This particular area of the Moon is sensational! The shallow angle that the Sun’s light is
illuminating the field reveals dozens of ancient lava flows. These flows reveal themselves with the
shadow of their leading edge. There is
also a rile to the north. Riles are
typically as a result of shrinkage of the lava flows.

Rile Hypatia is a very ancient valley. It was formed while the Moon still had lava
flowing freely. Evidence for this is the
flooded valley floor. The surface lava
field fractured due to cooling and subsurface lava pressure. The freshly opened gash filled with lava from
underneath.

The craters Armstrong, Aldrin and Collins are very recent
impacts compared to the surrounding lava
field. These three craters are
challenging to spot being so small. The
smallest is Collins with a diameter of 3km, Aldrin at 4 and Armstrong at close
to 5km. Due to their size, they are
visible only for a short time when the angle of the incident sunlight is
shallow enough to make their shadows prominent enough. Collins is the most challenging to see, and
requires a combination of good and stable atmospheric conditions and a minimum
aperture of 8” to spot it.

This sketch was a joy to lay down. Mare Tranquillitatis’ lava fields are full of
an intricate filigree network of lava flows.
The lunarscape is also pockmarked with dozens upon dozens of tiny
craters, three of which are named after three most important explorers.

Sunday, 22 June 2014

There is one thing about astronomy that is most challenging - the weather!

We are left totally to the mercy of the vagary and fickleness of the weather.

I have been wanting to do a sketch of the Moon for the last fortnight. Before the full Moon, persistent overcast conditions curtailed any chance. The four days around the full Moon were fine, but this phase though very challenging coincided with work commitments. This last week has been an exercise in sheer frustration - the days have been beautiful, clear ones, with little cloud. Yet each and every single night has seen cloud roll in either right on sunset, or at the very time I've planned to set up a telescope. This morning I got up at 3am, being confident that this wretched cloud would cease to be problematic as cloud had not appeared when I turned in for the night. At 3am, I looked out the window, and cloud was solid horizon to horizon!!! AAHHH, so frustrating!

Today I am presenting one of my most satisfying sketches, that of the giant globular cluster Omega Centauri.

Globular clusters present real challenges to illustrate. More orthodox illustration techniques struggle to overcome the texture of the paper, and lack the depth of density that is visible. Even more challenging with large globulars using large apertures of telescope is the sheer complexity of form and numbers of stars, and not extending the sketch far enough to give a surrounding context.

But, if a good technique is found, a sketch can produce an image that is not just vivid, but can reveal detail that is burnt out in photographs. With Omega Centauri, this burnt out feature is one of its signature markings "The Eye". Each globular cluster has what I like to describe as 'a unique fingerprint' - unique markings, strings of stars, patterns depth, and details. Omega's Eye is a coincidence of line of sight where a hollow appears formed by an apparent lack of bight stars in this spot at its core. Long exposure photographs reveal that there is no real lack of stars, and is purely a coincidence.

One thing about that makes Omega Centauri unique among the globular clusters that orbit the Milky Way is it if far from being 'normal' globular cluster. Omega is considered to be the remnant core of a smaller galaxy swallowed up by the Milky Way long, long ago. Evidence of this is more than its immense size. Its very size makes it too big to be normal globular. The only way that such a large number of stars can be stably maintained so tightly is if a black hole is at its core. Further evidence that Omega is not a typical globular cluster is the variation in age of the component stars. Typical globular clusters are made up of very old stars, evidenced by the absence of heavier elements in the spectrum of these stars. The stars of Omega vary in age, as the spectrum of the stars reveal heavier elements that are only formed from later stellar evolution.

This particular sketch was done using my 17.5" push-pull dobsonian from my home in Sydney.

Thursday, 5 June 2014

While I have my own set of objects and targets I have put in a "must sketch" list, the wider audience who may read my blog could have their own idea of what would make a good sketch target, or would like just to see what a particular target looks like through a telescope as sketching is as true-to-life as an image can be, or they may have a particular favourite astronomical object that they would like to see rendered as a sketch.I've started a poll that you will find in the left-hand column. This will be a preliminary poll to see what specific object types you would like to see sketched by me. Once the poll is concluded, I will compile a list of objects from the poll statistics. Once this poll is concluded, I will look to produce a sketch of the selected object.If you have a very specific astronomical object/target that you would like me to sketch, you are also welcome to let me know directly by emailing me or making a post on my blog.Keep in mind that different objects/targets will have an optimal window of opportunity to be sketched due to their seasonal track around the sky or due to their orbit. The weather is another unpredictable factor. But the selected objects will be sketched when the best opportunity presents.Alex.

The Moon is one of my favourite sketching subjects. It is always bright to make it an easy telescopic target from my home in Sydney. Another aspect is the occurrence of alphanumeric along the terminator, caused by the shallow incidence of sunlight provoking shadows on the cratered surface that to our eyes resemble letters and numbers. Another type of lunar apparition caused by incidental shadows is the appearance of other recognisable shapes and even animals.

My latest lunar sketch is one such shadow apparition.

I don't often have a particular target in mind. I typically start by scanning the length of the terminator looking for features that catch my attention as a sketching subject. The "terminator" is the junction line between the lit and dark edge of the lunar surface. On this occasion, a lovely set of flooded crater shadows forming the shape of 'A Little Fat Owl'.

The crater Fra Mauro forms the body, Parry the right eye, and Bonpland the left eye. The contours of the flooded Fra Mauro give the effect of plumage to the body.

Later while researching this area, I came to find out that the Apollo 14 landing site happens to be just below where the owl's feet would be.

Tuesday, 3 June 2014

Alexander's Astronomy Sketching is the site where I share my astronomical sketching, ideas, inspirations and motivations.

It is a place where the niche of astronomical sketching can be explored and learnt. Where techniques are examined and expanded, where the strengths of each and every instrument is celebrated, and where art and science meet.

I intend to share my experiences and work with you. Works that I have just completed. Places I travel to. People I meet. And hopefully inspire you to share your own thoughts, and even inspire you to put pencil to paper!

From our closest neighbour the Moon, to roving visitors of comets, the majestic planets and the wonders of the expanding cosmos - all interpreted through the media of illustration - the oldest form of astronomical imaging.